It is known that air filters may be used to filter combustion intake air for internal combustion engines in motor vehicles, for example, passenger vehicles, commercial vehicles, production machines, agricultural vehicles, but also stationary generators and the like. Such air filters usually comprise a housing, an air inlet and an air outlet, with a removable and replaceable main filter element situated in the housing. The housing often comprises a maintenance cover or access cover for access to the filter element accommodated in the interior for maintenance. The filter element may therefore be dismantled and either replaced by a brand-new filter element, overhauled and reused or exchanged with a used but overhauled filter element.
DE 20 2008 018 217 U1 describes an air filter system having an air filter housing and a serviceable air filter element. The serviceable air filter element is positioned, ready for operation, within a housing interior. The air filter element has a filter body extending between the first and second closing caps. The filter body surrounds and defines an open filter interior. The first closing cap is a closing cap that is open and has an air flow opening through it. The second closing cap is a closing cap that is closed and has an outer end surface. A housing sealing arrangement is provided on the first closing cap and is aligned to seal the air filter element with respect to the air filter housing and to hold it in the housing. A protruding/receiving arrangement is provided as an additional holding device, comprising first and second elements.
A first element of the protruding/receiving arrangement is positioned on the outer end surface of the second closing cap. It is to be brought into engagement with the access cover in a defined manner. A second element of the protruding/receiving arrangement is positioned on the access cover. It has a helical ring element and may be either a ring protrusion or a ring-shaped receiving groove. The first and second elements of the protruding/receiving arrangement engage with one another to supply a fixed holder of the air filter element on the second end. The first and second elements of the protruding/receiving arrangement are in non-rotatable engagement.
The filter elements of air filters are usually replaced after a certain period of operation. Depending on the amount of dust generated, the service life of an air filter may amount to a few days, for example, for use in construction machines, up to several months in environments with a lower dust burden.
In particular when filter elements are replaced frequently, secure and reliable sealing of the filter element in a housing is important. The sealing should be designed to be thermally stable and vibration-proof. Sealing of the filter element must also be ensured in installations or facilities exposed to extreme vibrations or shaking. At the same time, however, the filter element itself should preferably not have any metallic elements at all, so that it can be disposed of thermally with no problem.